net.corda.core.utilities

Class ProgressTracker

net.corda.core.utilities.ProgressTracker

public class ProgressTracker

A progress tracker helps surface information about the progress of an operation to a user interface or API of some kind. It lets you define a set of steps that represent an operation. A step is represented by an object (typically a singleton).

Steps may logically be children of other steps, which models the case where a large top level operation involves sub-operations which may also have a notion of progress. If a step has children, then the tracker will report the steps children as the "next step" after the parent. In other words, a parent step is considered to involve actual reportable work and is a thing. If the parent step simply groups other steps, then you'll have to step over it manually.

Each step has a label. It is assumed by default that the label does not change. If you want a label to change, then you can emit a class Change.Rendering object on the ProgressTracker.Step.changes observable stream after it changes. That object will propagate through to the top level trackers changes stream, which renderers can subscribe to in order to learn about progress.

An operation can move both forwards and backwards through steps, thus, a class ProgressTracker can represent operations that include loops.

A progress tracker is not thread safe. You may move events from the thread making progress to another thread by using the Observable subscribeOn call.

See Also:

class Change.Rendering, ProgressTracker.Step.changes, changes, class ProgressTracker

Field Detail

Companion

public static net.corda.core.utilities.ProgressTracker.Companion Companion

Deprecated.

Constructor Detail

ProgressTracker

public ProgressTracker(@NotNull
                       net.corda.core.utilities.ProgressTracker.Step... inputSteps)

A progress tracker helps surface information about the progress of an operation to a user interface or API of some kind. It lets you define a set of steps that represent an operation. A step is represented by an object (typically a singleton).

Steps may logically be children of other steps, which models the case where a large top level operation involves sub-operations which may also have a notion of progress. If a step has children, then the tracker will report the steps children as the "next step" after the parent. In other words, a parent step is considered to involve actual reportable work and is a thing. If the parent step simply groups other steps, then you'll have to step over it manually.

Each step has a label. It is assumed by default that the label does not change. If you want a label to change, then you can emit a class Change.Rendering object on the ProgressTracker.Step.changes observable stream after it changes. That object will propagate through to the top level trackers changes stream, which renderers can subscribe to in order to learn about progress.

An operation can move both forwards and backwards through steps, thus, a class ProgressTracker can represent operations that include loops.

A progress tracker is not thread safe. You may move events from the thread making progress to another thread by using the Observable subscribeOn call.

See Also:

class Change.Rendering, ProgressTracker.Step.changes, changes, class ProgressTracker

Method Detail

getSteps

@NotNull
public net.corda.core.utilities.ProgressTracker.Step[] getSteps()

The steps in this tracker, same as the steps passed to the constructor but with UNSTARTED and DONE inserted.

getCurrentStep

@NotNull
public net.corda.core.utilities.ProgressTracker.Step getCurrentStep()

Reading returns the value of stepsstepIndex, writing moves the position of the current tracker. Once moved to the class ProgressTracker.DONE state, this tracker is finished and the current step cannot be moved again.

See Also:

stepIndex, class ProgressTracker.DONE

setCurrentStep

public void setCurrentStep(@NotNull
                           net.corda.core.utilities.ProgressTracker.Step value)

Reading returns the value of stepsstepIndex, writing moves the position of the current tracker. Once moved to the class ProgressTracker.DONE state, this tracker is finished and the current step cannot be moved again.

See Also:

stepIndex, class ProgressTracker.DONE

getStepIndex

public int getStepIndex()

The zero-based index of the current step in the steps array (i.e. with UNSTARTED and DONE)

See Also:

steps

getStepsTreeIndex

public int getStepsTreeIndex()

The zero-bases index of the current step in a allStepsLabels list

See Also:

allStepsLabels

getCurrentStepRecursive

@NotNull
public net.corda.core.utilities.ProgressTracker.Step getCurrentStepRecursive()

Returns the current step, descending into children to find the deepest step we are up to.

getChildProgressTracker

@Nullable
public ProgressTracker getChildProgressTracker(@NotNull
                                                         net.corda.core.utilities.ProgressTracker.Step step)

setChildProgressTracker

public void setChildProgressTracker(@NotNull
                                    net.corda.core.utilities.ProgressTracker.Step step,
                                    @NotNull
                                    ProgressTracker childProgressTracker)

endWithError

public void endWithError(@NotNull
                         java.lang.Throwable error)

Ends the progress tracker with the given error, bypassing any remaining steps. changes will emit the exception as an error.

See Also:

changes

getParent

@Nullable
public ProgressTracker getParent()

The parent of this tracker: set automatically by the parent when a tracker is added as a child

getTopLevelTracker

@NotNull
public ProgressTracker getTopLevelTracker()

Walks up the tree to find the top level tracker. If this is the top level tracker, returns 'this'. Required for API compatibility.

getAllSteps

@NotNull
public java.util.List<kotlin.Pair> getAllSteps()

A list of all steps in this ProgressTracker and the children, with the indent level provided starting at zero. Note that UNSTARTED is never counted, and DONE is only counted at the calling level.

getAllStepsLabels

@NotNull
public java.util.List<kotlin.Pair> getAllStepsLabels()

A list of all steps label in this ProgressTracker and the children, with the indent level provided starting at zero. Note that UNSTARTED is never counted, and DONE is only counted at the calling level.

nextStep

@NotNull
public net.corda.core.utilities.ProgressTracker.Step nextStep()

Iterates the progress tracker. If the current step has a child, the child is iterated instead (recursively). Returns the latest step at the bottom of the step tree.

getChanges

@NotNull
public rx.Observable<net.corda.core.utilities.ProgressTracker.Change> getChanges()

An observable stream of changes: includes child steps, resets and any changes emitted by individual steps (e.g. if a step changed its label or rendering).

getStepsTreeChanges

@NotNull
public rx.Observable<java.util.List> getStepsTreeChanges()

An observable stream of changes to the allStepsLabels

See Also:

allStepsLabels

getStepsTreeIndexChanges

@NotNull
public rx.Observable<java.lang.Integer> getStepsTreeIndexChanges()

An observable stream of changes to the stepsTreeIndex

See Also:

stepsTreeIndex

getHasEnded

public boolean getHasEnded()

Returns true if the progress tracker has ended, either by reaching the class ProgressTracker.DONE step or prematurely with an error

See Also:

class ProgressTracker.DONE